This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Nature has given us a tremendous amount of structurally diverse natural products which we use to combat diseases ranging from the common cold to cancer. The question of how bacteria and other organisms make these compounds needs to be investigated. We are investigating several proteins that have very interesting activity in their biosynthetic pathways. LnmQ is an adenylation domain in the leinamycin biosynthetic pathway which specifically activates D-Ala. This is the only known adenylation domain to be specific for the unnatural stereoisomer. This proposal will use the technique of X-ray crystallography to determine exactly how this enzyme works mechanistically and how it can recognize a small hydrophobic side chain such as that of D-Ala. Native and Se-Met crystals have been grown for this protein. They have been screened at our home source and we have been able to get information regarding space group and unit cell dimensions. LnmQ has a space group of C2 and a unit cell of a=97.714, b=102.412, c=79.008 with [unreadable]}[unreadable][unreadable]=90, [unreadable]}[unreadable][unreadable]=116.973, [unreadable]}[unreadable][unreadable]=90.